A particle moves along the -axis so that its position at time t > 0 is given by x (t) = 12-9 31 2 +8 (a) Show that the velocity of the particle at time t is given by v (t) = 70t (3t2 +8) (b) Is the particle moving toward the origin or away from the origin at time t = 2 ? Give a reason for your answer. (c) The acceleration of the particle is given by a (t). Write an expression for a (t), and find the value of a (2). (d) What position does the particle approach as t approaches infinity